1 Field of the Invention
The present invention generally relates to an image reading device, an apparatus including the image reading device, an image reading control method, and a recording medium storing an image reading control program.
2. Description of the Related Art
With the increased needs for electronic data, various image processing apparatuses are widely used such as printers, facsimiles, scanners, copiers, or multifunctional apparatuses capable of performing a plurality of image processing functions.
Of the plurality of image processing functions, the function of image reading, which may be performed by the scanner, is carried out using an optical sensor that converts optical information read from an image to an electric signal. The optical sensor needs to be regularly calibrated, such that the tone of the image subjected for reading, matches the tone of 5 image data generated by reading the image. For example, a value read from a measurement pattern printed on a recording sheet is compared with a reference value to correct the reading characteristics of the optical sensor.
In one example, when the optical sensor is implemented as a line sensor in which a plurality of optical sensors are arranged in a sub-scanning direction, the line sensor may be calibrated as described in Japanese Patent Application Publication No. 2010-114498-A. In an image forming apparatus described in the Japanese Patent Application Publication No. 2010-114498-A, a calibrator having a polygonal shape, which is rotatable in the backside of a recording sheet, is provided at a reading position to be read by the sensor in a sheet transfer path. The sensor is calibrated when there is no recording sheet being transferred in the sheet transfer path.